325 Transplant

[MattA 165]

My first Bimmer a 320i '87 only to discover aftre a few weeks that it wasn't all it seemed.. so after much research decided to repower with 2.5ltr. Everything bolts straight in but be prepared to do a lot of cussin as the electrics were a headache..

Way worth it but.. I have heaps of Information if anyone is thinking of goiong down this path..

[Gus 5]

if you could do a write up it would be sweet.....its a pretty interesting swap if its as easy as you say.....did you have a whole donor car? or just the engine? did you have to swap from L jet to motronic? and did you do the electrics yourself? let us know

cheers and welcome to the site

[Grant 4]

Gus

With mine (motronic) there was no need to swap the elctronics as well. I still have all of the 320i electrics and ECU (with a 325i chip) in it.

Cheers

[Guest Zwilling]

I've got a 1990 320 and am looking to up the ante, is it worth upgrading the chip instead of finding a replacement engine??? if yes where can one find a chip upgrade???

Edited May 3, 2004 by Zwilling

[bumpstop325 0]

it is a complete waste of time and breath to even think about it.

this is a last resort when you have done your cam, stroked, jacked up compression, port n polish. then do it.

[Grant 4]

Yeah Tim is right, I really don't think it is worth chipping the car unless you are upgrading other things as well, like intake, headers, exhaust etc.

Without doing these other things, the bang for your buck is not likely to be very good.

BTW welcome to the site.

Cheers

[Guest Zwilling]

Thanks

I'm currently in the state of mind that it'd be easier to just buy a newer model rather than messing with it - but it's the sentimental attachment...

[Viking 0]

If your keen at looking at engine swaps (M/S50) there is a very good email list on yahoo, E30TwinCam that alot of people are on spreading advice.

Worth a look if you want to go down that path.

[MattA 165]

Mine was/is L-Jetronic the 325 engine came with Motronic loom, computer and airflow meter but required the crank position and speed sensors in the bell housing of the gearbox and after getting everything in the cars wiring was not compatable with the Motronic system.

Easy way round is to sell the Motronic loom and computer and use the L-Jetronic this entails fitting the distributer from the 320 to the 325 block (just pull the blank and fit check that you get the dissy aligned correctly or the timing will be way out)

use the leads from the 320. take the distributer off the cam shaft on the 325 and fabricate a cover (don,t laugh but I used an aluminium pot lid polished but).

You need to fit the temp idle valve thingy from the 320 and do away with the Motronic ICV also need the vacuum fittings off the 320 intake manifold. You need to install vacuum advance/retard lines on the throttle body there is a blank that you can use for 1 the other I drilled and tapped and used a 2mm gas fitting (grind and polish the inside of the throttle body or it will whistle like a sheep fiddler). I tried to locate them as close as possible to the same postition as on the 320 throttle body as best as I can tell the only real crtical thing is that the internal diameter is the same as on the 320 throttle body otherwise it over advances/retards.

The air flow meter from the 320 works sweet (the 325 one wouldn't work and they are the same diameter) the only other things that I can think of where some adaptation of the radiater hoses and a bit of fiddling to get the timing right nothing too tricky the fuel air mix is still not right but that due to me not using a CO/2 meter (it runs a bit rich).

I did the whole job in our garage with the bare minium of tools (a cheap set of ring spanners a warehouse socket set and a few tool that I found in my father-in-laws shed (he's a builder) My experiance with mechanics is until this project limited an engine swap on a HQ wagon, oil changes etc. My greatest souse of information came from the public library and internet. Total cost about $1500 but it did take me a lot of time. I don't know how much power I have gained but it's a whole shitload of fun now..

If anyone wants more info let me know

[Gus 5]

sounds bloody good...nice effort.....and the advantage of using l jet is that you now have adjustable timing! put some avgas in there...and go hard! rad....so cool....

[MattA 165]

with gas the price it is at the moment AVGAS might be an economical option..

So what do I need to do to the timing if I was to burn some avgas?

[Guest Zwilling]

As as aside, does anyone know what the % of ethanol added to our petrol??? Did you know that Fonterra produces a sh*t load of ethanol, a major by product of production, some goes into the cheap vodka and some must go into petrol but where does the rest of it go???

[318i Turbo 0]

u will b lucky to get a gain out of avgas over 98 on a higher reving engine as the flame front(burn)rate it to slow, which is why formula fords etc use pump gas. i recomend 98 with an aditive that i get from pioneer auto parts its a sh*t that increases the oxagen giving u a bigger bang(its not octane booster)i post up the name of the stuff and price when i find a bottle

[E30-323ti 66]

as the flame front(burn)rate it to slow

That is why you can ADVANCE the timing!!!

[318i Turbo 0]

yes i know but with the timing ADVANCED it isnt making it burn any faster it only makes it burn earlyer which isnt giving it the sort of bang to get more power out of a steet motor, it fine to be running it on perpose built race motor but that is built it run on it

[Guest Andrew]

yes i know but with the timing ADVANCED it isnt making it burn any faster it only makes it burn earlyer which isnt giving it the sort of bang to get more power out of a steet motor, it fine to be running it on perpose built race motor but that is built it run on it

The 320 sure has a long more power from a large timing advance - much better fuel economy also.

[318i Turbo 0]

yes it will to a extent it all depends on the fuel you use and how much fuel the motor is being given(rich or lean)

[318i Turbo 0]

i just found this http://forums.bimmerforums.com/forum/showt...ad.php?t=207198

they are having the same chat

[Guest Andrew]

yes it will to a extent it all depends on the fuel you use and how much fuel the motor is being given(rich or lean)

Mine is running 98 with the fuel pressure increased only a tad.

[gmccormack 0]

Mine was/is L-Jetronic the 325 engine came with Motronic loom, computer and airflow meter but required the crank position and speed sensors in the bell housing of the gearbox and after getting everything in the cars wiring was not compatable with the Motronic system.

Easy way round is to sell the Motronic loom and computer and use the L-Jetronic this entails fitting the distributer from the 320 to the 325 block (just pull the blank and fit check that you get the dissy aligned correctly or the timing will be way out)

use the leads from the 320. take the distributer off the cam shaft on the 325 and fabricate a cover (don,t laugh but I used an aluminium pot lid polished but).

You need to fit the temp idle valve thingy from the 320 and do away with the Motronic ICV also need the vacuum fittings off the 320 intake manifold. You need to install vacuum advance/retard lines on the throttle body there is a blank that you can use for 1 the other I drilled and tapped and used a 2mm gas fitting (grind and polish the inside of the throttle body or it will whistle like a sheep fiddler). I tried to locate them as close as possible to the same postition as on the 320 throttle body as best as I can tell the only real crtical thing is that the internal diameter is the same as on the 320 throttle body otherwise it over advances/retards.

The air flow meter from the 320 works sweet (the 325 one wouldn't work and they are the same diameter) the only other things that I can think of where some adaptation of the radiater hoses and a bit of fiddling to get the timing right nothing too tricky the fuel air mix is still not right but that due to me not using a CO/2 meter (it runs a bit rich).

I did the whole job in our garage with the bare minium of tools (a cheap set of ring spanners a warehouse socket set and a few tool that I found in my father-in-laws shed (he's a builder) My experiance with mechanics is until this project limited an engine swap on a HQ wagon, oil changes etc. My greatest souse of information came from the public library and internet. Total cost about $1500 but it did take me a lot of time. I don't know how much power I have gained but it's a whole shitload of fun now..

If anyone wants more info let me know

wouldn't it have been easier to buy the right g/box with the holes for the crank angle/speed sensor in it??

[MattA 165]

looked at that option but all the info and advice I could find pointed to many hours at the Auto Electirtians matching the cars wiring to the Motronic system..had 2 auto sparkies look at it and both said $500+ and the $400 or so for the gearbox. In the long run it may have been a better option as Motronic is a newer system but was a student at the time $900 may as well have been $9000..